Batescrew
BUTTON VALVES


Button Valve with Gasket

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     Dimensions     Deep Installations

This is a fully self contained sealing system, somewhat more substantial than the traditional button valve.  The most common application is for sealing upriser pipes entering open channels.  Valves are made in sizes matching the inside diameter of Class 2 concrete pipe.
Flutter of the door, a common cause of fatigue cracking in button valves, is eliminated by the roller guides, which also provide the stability necessary for the valve to be mounted in positions other than vertical.
A stainless steel seat, built into the valve, avoids the need for the end of the pipe to have a true sealing surface.
The control screw and ball thrust bearing are contained in a dust-proof housing, above water level.

Nominal bore (mm)  and maximum On-Seating / Off-Seating pressure (metres head).

 

300

375

450

525

600

675

750

900

1050

1200

1350

1500

1650

1800

On/Off

6/6

6/6

6/6

6/6

6/6

6/6

6/6

6/6

6/4.5

6/3.4

6/2.7

6/2.2

6/1.8

6/1.5

Corrosion Resistance.  Normal construction is of mild steel, hot dip galvanised.  Stainless Steel, in grades 304L or 316L, may also be specified.

Sealing Method.  A stainless steel sealing ring is welded to the top lip of a steel spigot, located in the base of the valve.  An  extruded rubber seal is glued and riveted into a recess on the underside of the door.  As the two are clamped together, a substantial channel-section reinforcing collar prevents distortion of the lower flange and seat.  Eight 50mm dia. bronze rollers, mounted on 25mm stainless shafts, guide and stabilize the door.

Screw Mechanism.  Developed by Batescrew, this comprises a jam-resisting 'Acme' thread, machined from grade 304 stainless steel, with bronze nut and ball thrust bearing.  The handwheel is non-rising, due to a telescopic lifting tube and the screw does not protrude above the handle, enabling rapid winding.

Handwheels  The standard handwheel is removable, with a tapered socket to engage  the control thread.  One bolt secures the handwheel in normal use.

Installation.  A square base flange allows for bolting to any flat surface or concrete pipe collar.  We recommend the use of stainless steel chemical anchor bolts and gaskets of compressible bitumen-impregnated foam , as seen in the illustration.  The gasket material is initially 50mm by 50mm in square section, compressing to approximately 10mm.  All valves in the range are secured with 12mm bolts.

Installation Kit.  Valves are supplied with the following items:
     Gasket material, in 2m strips, plus adhesive.
     Square washers.
     Chemical anchor bolt kits with instruction sheet.
     Masonry drill bit to suit anchor bolt capsules.

Sizes and Pressure Rating   Button valves are available in a range of sizes to suit Class 2 concrete pipe.  The following table gives nominal bore and maximum static pressure rating for each valve.  Pressure ratings are on-seating and off-seating, the latter being pressure applied to the valve from below.